V-belt pulley

ABSTRACT

A pair of belt transmission flanges are mounted on a rotatable shaft with at least one of the flanges biassed in direction toward and axially movable to and from the other flange so as to adjust the width of the belt gap defined between the two flanges. The at least one movable flange comprises a hub, the inner peripheral surface of which spacedly surrounds the outer cylindrical surface of the rotatable shaft with a pair of bearing members axially spaced between and in contact with these surfaces. A torque transmitting member interconnects the at least one movable flange with the rotatable shaft so as to effect rotation of the former with the latter.

D United States Patent 1151 3,636,785 Weindler et al. 45 J 25, 1972 [54]V BELT UL 3,174,348 3/1965 Luenberger ..74/230.17 C I 3,358,520 12/1967Heydlauf et al. ..74/230.l7 C {72] Inventors: Berno Weindler, Wiesloch,Baden; Robert 3,400,600 9/1968 Ruprecht et al ..74/230.17 C Ruprecht,Aichelberg Kreis Esslingen 3,434,641 3/1969 Ambros 1 ..74/230.17 C amlleckar; Heinrich Grimm, Raid- 3,504,560 4/1970 Wunsch "74/230117 Cwangen Kreis Nurtingen, all of Germany I Primary ExaminerC. J. Husar[73] Ass1gnee. Ernst Heinkel Aktiengesellschaft, Stutt- Afl0mey MichaelS4 Striker gart-Zuffenhausen, Germany [22] Filed: Nov. 26, 1969 [57]ABSTRACT [2]] Appl. No.: 880,235 A pair of belt transmission flanges aremounted on a rotatable shaft with at least one of the flanges biassed indirection toward and axially movable to and from the other flange so as[30] Forms Apphcauon Pnonty Dam to adjust the width of the belt gapdefined between the two Nov. 30, 1968 Germany ..P 18 11 935.2 flangesThe at least one movable flange Comprises a hub, the inner peripheralsurface of which spacedly surrounds the [52] U.S. Cl ..74/230.17 outercylindl'ical Surface of the rotatable Shaft with a 1121ir 0f 51 m C| 155 52 bearing members axially spaced between and in contact with [58]Field of Search ..74 230.17 these Surfaces A tOrqne transmitting memberinlercnnnacts the at least one movable flange with the rotatable shaftso as to I 5 References Ci effect rotation of the former with thelatter.

UNITED STATES PATENTS 22 Claims, 3 Drawing Figures 2.952.161 9/1960Williams ..74/230.l7 C I PATENYEDJW 512572 SHEET 1 [IF 2 Fig. 7

INVENTOR V-BELT PULLEY BACKGROUND OF THE INVENTION The present inventionrelates in general to an adjustable V- belt pulley and more inparticular to improvements in mounting the axially reciprocable flangeor flanges on rotatable shafts or guide rods of the pulley of acontinuously variable drive arrangement.

Such drive arrangements are known and utilize adjustable feed beltswhich pass around a pulley coupled to a shaft from which or to whichpower is to be transmitted. In order to permit continuous powervariation, it is necessary that such pulleys be adjustable, and theytherefore usually comprise two flanges mounted on a series of guide rodswhich extend parallel with the drive shaft and with at least one of theflanges axially movable relative to the other flange which, likewise,may be movable or fixed. Between themselves, the inclined opposedsurfaces of the two flanges define a V-shaped groove in which the feedbelt is received. To achieve continuous variation of the drivearrangement, the movable flange shifts axially away from the fixedflange, or in case of two movable flanges, away from each other, to agreater or lesser degree and the feed belt is supported at a greater orsmaller distance from the shaft by engagement with the opposed surfacesof the two flanges. In addition, the movable flange or flanges must beable to perform only axial movements and must be secured againstrotation relative to the shaft member.

Axial shifting of the movable flange or flanges not only serves to varythe transmission of power by varying the tension of the feed belt butalso to equalize the variation in width of the belt. Such variations areto be found even in new belts.

In such hitherto known variable drive arrangements, the respectiveflanges usually are a casting from aluminum or gray cast iron, and themovable flange or flanges are provided with an elongated hub member inwhich a bushing or sleeve is accommodated. This bushing or sleevecomprises annular recesses along its inner periphery and in which annuliof roller bearings were seated for axial rolling movement of the movableflange on the guide rods.

Outside of the region of the bushing, the hub member is provided with aplurality of end bores in which guide bolts are slidably received andwhich guide bolts slidably interconnect the movable flange member withthe rotatable shaft in order to transmit the torque of the latter to theformer.

Such movable flanges either are self-adjustable by means of a springmember annularly surrounding the hub member and biassed between abutmentmembers on the movable flange and on the shaft, or are mechanicallyadjustable, for example, by means of roller bearing elements which,comprises an inner race fixedly connected to a shoulder on the movableflange and an outer race movable relative to the inner race andsubjected to exterior pressure to axially move the movable flangetowards the other flange.

Such variable drive arrangement, however, are uneconomical and expensiveas regards their construction and maintenance.

For example, the elongated extended hub member of the movable flangenecessitates voluminous space for reasons that the same has toaccommodate the guide rods in their respective dead end bores, theroller bearing arrangement or the spring member to axially bias themovable flange, and the roller bearing and sleeve arrangement to axiallyshift the movable flange in response to said biassing of the same.

In addition, the recesses fonned in the sleeve to accommodate the rollerbearings have to be extremely precise and overall symmetric so as toavoid obliquity and tilting of the movable flange and, thereby,consequent malfunctioning of the feed belt which would negatively affectthe durability of the same.

SUMMARY OF THE INVENTION Object of the present invention is to provide avariable drive arrangement incorporating a V-belt pulley which is simpleas regards its construction, economical as regards its manufacture, andwhich provides an improvement in mounting the axially reciprocable partsor analogous structure on the rotatable shafts or guide rods.

Such a variable drive arrangement with a V-belt pulley according to thepresent invention comprises a rotatable shaft member having an outercylindrical surface with a first and a second flange member mounted onthe shaft member with at least one of the flange members axially movablerelative to the other of said members. A hub member is fixedly connectedwith the at least one movable flange member and comprises an innerperipheral surface spacedly surrounding the outer cylindrical surface ofthe shaft member. First and second bearing means spaced in axialdirection of the shaft member are accommodated between and in contactwith the said surfaces and biassing means constantly bias the at leastone movable flange member in direction toward the other of the saidflange members. The biassing means is constantly positioned into contactwith the at least one movable flange member and the torque of the shaftmember is transmitted to the at least one movable flange member by meansof a member interconnecting the former and the latter.

The novel features which are considered as characteristic for theinvention are set forth in particular in the appended claims. Theinvention itself, however, both as to its construction and its method ofoperation, together with additional objects and advantages thereof, willbe best understood from the following description of specificembodiments when read in connection with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 shows a cross-sectional view ofa mechanically adjustable V-belt pulley according to the presentinvention and illustrating an upper portion of the pulley in which themovable flange has been axially moved toward the fixed flange, and alower portion of the pulley in which the movable flange has been axiallymoved away from the fixed flange;

FIG. 2 shows an arrangement as in FIG. 1, however, with the respectiveaxially shifted movable flanges self-adjustable by a spring member; and

FIG. 3 shows a further embodiment of a self-adjustable V- belt pulleyincorporating two axially movably mounted flanges with the upper flangesin a more compressed condition and the lower flanges in a substantiallyspread condition.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring now to the drawings,FIGS. 1 illustrates an adjustable V-belt pulley which comprises arotatable shaft I having an outer cylindrical surface, a flange 2 fixedat one end of the shaft 1 and welded thereto, and a flange 3 axiallymovably mounted on the shaft 1 and having an inner peripheral surfacespacedly surrounding the outer cylindrical surface of the shaft. Therespective flanges are pressed from sheet metal and, between themselves,the inner inclined and opposed flange surfaces 5 define a V-shapedgroove in which a feed belt 4 is adjustably received.

Laterally fixed to the movable flange 3 by soldering, is an annularsleeve or hub member 6 which comprises a plurality of bores 7 each ofwhich slidably accommodates one of a plurality of guide rods 8 which attheir outer end are fixed and soldered to an annular disc-shaped rodsupport 9 which, preferably by soldering, are fixedly connected to athreaded ring member 12. The ring member 12 is screwed onto the free endof the shaft 1 and secured against loosening therefrom by means of afilling or adhesive material.

The sleeve 6 essentially consists of a hardenable steel and comprises inthe regions of its axially spaced ends two bearing projections 13unitary with the inner peripheral surface of the sleeve 6 and engagingof the outer cylindrical surface of the shaft 1 for axially slidablemovement thereon. The sliding surfaces of the bearing projections 13 arearcuately shaped and hardened, and are fine cut relative to the diameterof the outer cylindrical surface of the shaft 1 and a clearance orsliding tolerance such that the movable flange 3 onto which the torqueof the shaft 1 is to be transmitted by the guide rods 8, is easilyaxially shiftable along the outer cylindrical surface of the shaft 1. Asa result of the positioning of the slidable bearing members at theaxially opposite ends of the sleeve 6, the relationship between thelength of the sleeve and the diameter of the movable flange becomes morefavorable as regards the tilting angle of the latter. In addition. thespace defined between the two bearing projections 13, on the one hand,and the inner peripheral surface of the sleeve 6 and the outercylindrical surface of the shaft 1, on the other hand, constitutes arelatively large compartment 14 which, filled with a lubricant, ensuresa suitable lubrication for the moving parts for the entire duration ofthe drive arrangement.

Flanking the bearing projections 13 at axially opposite ends of thesleeve 6 and accommodated in the annular recesses formed at these ends,are a pair of O-rings 16 which serve to seal the compartment 14. Attheir outer ends, the O-rings are enclosed, at the one hand, by theflange 3 and, at the other hand, by a seal ring 15.

The sleeve 6 is formed with an annular shoulder 17 which, in theembodiment shown in FIG. 1, is provided with the inner race 18 of anannular roller bearing arrangement 19. The inner race 18 is fixedlypressed onto the shoulder 17 while the outer race 18a of the arrangement19 is rotatable and operatively engaged by a mechanical biassing member,not shown, which serves to bias or press the movable flange 3 indirection toward the fixed flange 2.

With the present embodiment of the drive arrangement according to theinvention and which incorporates a relative compact sleeve or hub havinga corresponding outer diameter, it is made possible to utilize rollerbearings which, when used with identically dimensioned flanges, can betwice as small as the roller bearings hitherto used for this purposewhich, all around, is quite economical.

The embodiment of the variable drive arrangement shown in FIG. 2, isself-adjustable, i.e., instead of the mechanically actuated rollerbearing arrangement 19 of FIG. 1, a spring member 21 is provided to biasthe movable flange 3 in direction toward the fixed flange 2.

The spring member 21, at the one hand, abuts against and is supported bya bracket or flange 11 which is soldered to the guide rods 8 and thethreaded ring 12' screwed onto the free end of the shaft 1' and, on theother hand, abuts against and is supported by a flange ring 22 which, inturn, abuts against an annular shoulder 17' of the sleeve 6.

The end portions or windings of the spring member 21, preferably, areprovided with plastic rings 23 and which are embodied such as to effectcentering the balancing of the spring member 21.

In order to prevent the admittance of dirt and dust into the springregion and consequent malfunctioning of the spring member, the latter isenclosed in telescopically overlapping plastic caps 24 which areaccommodated in convexities in the bracket 11 and the flange ring 22,respectively, and are retained in the same under the spring force of thespring member 21.

The embodiment shown in FIG. 3 is seen to be self-adjustable and toincorporate two axially movable flanges instead of one.

This arrangement is embodied such that the movable flanges 2 alwaysretain the feed belt 4 centrally of the drive arrangement, i.e., midwayof the rotatable shaft, with the belt either in its highest or lowestposition between the flanges 2'.

The operation of the respective movable flanges 2' and their generalarrangement on the rotatable shaft is analogous with that of the movableflange 3' of FIG. 2, however, with the exception that the upper portionof the drive arrangement is seen to comprise annular recesses 28 in thesleeve 6' and in which a pair of annular roller bearing elements 29 areaccommodated. These elements 29 are in rolling contact both with theinner peripheral surface of the sleeve 6' and the outer cylindricalsurface of the rotatable shaft and permit the movable flanges 2 to beaxially shifted under the bias of the spring member.

The bearing surfaces 31 are hardened. Such hardening of the bearingsurfaces may be effected, for example, by coating the same with a layerof hard chromium.

Flanking the roller bearing elements 29 at their outer ends and outerraces 33 integrally formed with the sleeve 6' and having an innerperipheral diameter which is larger than the diameter of the outercylindrical surface of the shaft so as to not abut against or engage thesame.

Provided intermediate the two roller bearing elements 29 is a spacermember which is held by a dowel pin 34 and serves to keep the spaceslotted for each of the roller bearing elements, constant. Axiallyinserted into the recess formed between the inner periphery of the outerraces 35 and the outer cylindrical surface of the shaft, is a buttingand sealing ring 35 and, as in the embodiments of FIGS. 1 and 2,accommodated in the recesses at the free ends of the sleeve 6' is anO-ring 16.

In the embodiments shown in FIGS. 1, 2 and 3, each of the dead-end bores7 arranged in the sleeves to guide the slidable guide rods 8, 8, isprovided at their open ends with a sliding sleeve 27 which are made of aplastic material and have spaced ends with a slanting slit extendingfrom one end to the other.

This slit permits a much closer restraint on the tolerance between theguide rods and the sliding sleeves since the strength of the plasticsliding sleeves can much easier be kept within close tolerance limitsthan their respective outer or inner diameter, especially since duringinsertion of the sliding sleeves into the dead-end bores or duringinsertion of the guide rods into the sliding sleeves and with but aslight variation in either the tolerance of the outer diameter of theguide rods or the inner diameter of the dead-end bores, these outer orinner diameters of the sliding sleeve can change so extensively relativeto each other that the guide rods 8 can easily be jammed in the guidesleeves.

The plastic sliding sleeves are axially secured in the deadend bores bymeans of the sealing ring 15 which, by means of an inwardly flanged sideportion of the sleeve 6, are retained in the same. In conventionalembodiments such sealing rings usually are retained or connected by atleast three screw members, however, such a connection is of courseuneconomical and in addition, and in view of the relatively smalldiameters of the sealing rings 15 and the ring-shaped guide rod carriers9, the roller bearing arrangements 19 may easily be stripped from thesleeves 6, 6, without the hitherto required initial removal of othercomponents.

It will be appreciated that the respective bearing elements, i.e., thesliding projections 13 and the roller bearings 29, may be positionedeither on the inner peripheral surface of the sleeves, as describedhereinbefore, or on the outer cylindrical surface of the rotatableshafts, depending on the nature of the application of the drivearrangement.

Consequently, the scope of the subject application is not to be limitedto the above arrangement as described with reference to the variousembodiments shown in the attached drawings.

Without further analysis, the foregoing will so fully reveal the gist ofthe present invention that others can be applying current knowledgereadily adapt it for various applications without omitting featuresthat, from the standpoint of prior art, fairly constitute essentialcharacteristics of the generic or specific aspects of this invention.

What is claimed as new and desired to be protected by Letters Patent isset forth in the appended claims:

1. In a sheave, a combination comprising a rotatable shaft member havingan outer cylindrical surface; a first and a second sheet metal flangemember mounted on said shaft member, at least one of said flange membersbeing axially movable relative to the other; a hub member fixedlyconnected to said at least one movable sheet metal flange member andhaw'ng an inner peripheral surface spacedly surrounding said outercylindrical surface of said shaft member; first and second bearing meansspaced in axial direction of said shaft member between and in contactwith said surfaces; means on 1 said hub member for transmitting abiasing force to said hub member and the flange member connected theretofor biasing said at least one movable flange member towards the otherflange member; and means for transmitting a torque between said shaftmember and said at least one movable flange member.

2. In a sheave as defined in claim 1, wherein said means fortransmitting a biasing force to said hub member comprises a rollerbearing having an inner race surrounding and fixed to said hub memberand an outer race rotatably surrounding said inner race and engageableby a biasing force.

3. In a sheave as defined in claim 1, and including biasing means inform of a spring member surrounding said hub member and having oppositeends, one of said ends being connected to said one movable flange memberand retaining means positioned on said shaft member and retainablyengaging the other of said ends of said spring member.

4. In a sheave as defined in claim 1, wherein said at least one movableflange member has axially opposite ends with one of said opposite endsfacing said other of said flange members and with said hub member fixedto the other of said opposite ends.

5. In a sheave as defined in claim 1, wherein said first and secondbearing means each comprises an annulus of rolling elements accommodatedand retained in a circumferential recess formed in one of said surfaces.

6. In a sheave as defined in claim 5, wherein said circumferentialrecesses are formed in said inner peripheral surface of said hub member.

7. In a sheave as defined in claim 5, wherein said rolling elementsinclude bearing surfaces in rolling contact with said surfaces of saidhub member and said shaft member, and wherein said rolling elements atleast in the region of said bearing surfaces consist of a hardenedmaterial.

8. ln a sheave as defined in claim 1, wherein said first and secondbearing means each comprises a circumferential projection unitary withone of said surfaces and having a peripheral surface in sliding contactwith the other of said surfaces.

9. ln a sheave as defined in claim 8, wherein said circumferentialprojections are unitary with said inner peripheral surface of said hubmember and external radially inwardly therefrom.

10. In a sheave as defined in claim 8, wherein the sliding surfaces ofsaid circumferential projections are arcuately shaped.

11. In a sheave as defined in claim 8, wherein said sliding surfaces arehardened and define an internal opening having a diameter which exceedsthat of said shaft member by a predetermined tolerance.

12. In a sheave as defined in claim 4, wherein said other of said flangemembers is a stationary member unitary with said shaft member, andwherein said hub member is unitary with said one movable flange member.

13. In a sheave as defined in claim 12, wherein said stationary flangemember and said shaft member, at the one hand, and said one movableflange member and said hub member, at the other hand, are bonded to eachother.

14. In sheave as defined in claim 3, and further comprising a shoulderportion in said hub member, said shoulder portion constantly engagingsaid one of said ends of said spring member.

15. In a sheave as defined in claim 3, wherein said retaining meanscomprises a bracket member fixedly secured at one end of said shaftmember and facing said one movable flange member.

16. In a sheave as defined in claim 3, wherein said retaining meanscomprises a flange member fixedly secured at one end of said shaftmember and facing said one movable flange member.

17. In a sheave as defined in claim 14, and further comprising a flangemember seated against said shoulder portion intermediate the same andsaid one of said ends of said spring member.

18. In a sheave as defined in claim 1. Wherein said hub member comprisesat least one axially extending bore; and wherein said torquetransmitting means comprises at least one elongated rod member havingopposite ends with one of said opposite ends slidably received in saidat least one bore in said hub member, and a retaining ring fixedlymounted on said shaft member axially spaced from said hub member andfixed with the other of said opposite ends of said rod member.

19. In a sheave as defined in claim 18, said hub member comprising afirst portion facing said one movable flange member and a second portionfacing said retaining ring, said means for transmitting a biassing forceto said hub member comprising a roller bearing having an inner racesurrounding and fixed to said second portion of said hub member and anouter race rotatably surrounding said inner race, and wherein saidsecond portion of said hub member and said retaining ring haverespectively outer diameters not exceeding the inner diameter of saidinner race.

20. In a sheave as defined in claim 19, wherein said at least one borein said hub member is provided with an inner sleeve member slidablyguiding said at least one rod member.

21. In a sheave as defined in claim 20, wherein said inner sleeve memberis made of a plastic material having a low coefficient of friction, saidsleeve having spaced ends and being provided with a slit extending fromone to the other of said spaced ends.

22. In a sheave as defined in claim 1, wherein said other of said flangemembers is a reciprocable flange member axially movable relative to saidone of said movable flange members.

1. In a sheave, a combination comprising a rotatable shaft member havingan outer cylindrical surface; a first and a second sheet metal flangemember mounted on said shaft member, at least one of said flange membersbeing axially movable relative to the other; a hub member fixedlyconnected to said at least one movable sheet metal flange member andhaving an inner peripheral surface spacedly surrounding said outercylindrical surface of said shaft member; first and second bearing meansspaced in axial direction of said shaft member between and in contactwith said surfaces; means on said hub member for transmitting a biasingforce to said hub member and the flange member connected thereto forbiasing said at least one movable flange member towards the other flangemember; and means for transmitting a torque between said shaft memberand said at least one movable flange member.
 2. In a sheave as definedin claim 1, wherein said means for transmitting a biasing force to saidhub member comprises a roller bearing having an inner race surroundingand fixed to said hub member and an outer race rotatably surroundingsaid inner race and engageable by a biasing force.
 3. In a sheave asdefined in claim 1, and including biasing means in form of a springmember surrounding said hub member and having opposite ends, one of saidends being connected to said one movable flange member and retainingmeans positioned on said shaft member and retainably engaging the otherof said ends of said spring member.
 4. In a sheave as defined in claim1, wherein said at least one movable flange member has axially oppositeends with one of said opposite ends facing said other of said flangemembers and with said hub member fixed to the other of said oppositeends.
 5. In a sheave as defined in claim 1, wherein said first andsecond bearing means each comprises an annulus of rolling elementsaccommodated and retained in a circumferential recess formed in one ofsaid surfaces.
 6. In a sheave as defined in claim 5, wherein saidcircumferential recesses are formed in said inner peripheral surface ofsaid hub member.
 7. In a sheave as defined in claim 5, wherein saidrolling elements include bearing surfaces in rolling contact with saidsurfaces of said hub member and said shaft member, and wherein saidrolling elements at least in the region of said bearing surfaces consistof a hardened material.
 8. In a sheave as defined in claim 1, whereinsaid first and second bearing means each comprises a circumferentialprojection unitary with one of said surfaces and having a peripheralsurface in sliding contact witH the other of said surfaces.
 9. In asheave as defined in claim 8, wherein said circumferential projectionsare unitary with said inner peripheral surface of said hub member andexternal radially inwardly therefrom.
 10. In a sheave as defined inclaim 8, wherein the sliding surfaces of said circumferentialprojections are arcuately shaped.
 11. In a sheave as defined in claim 8,wherein said sliding surfaces are hardened and define an internalopening having a diameter which exceeds that of said shaft member by apredetermined tolerance.
 12. In a sheave as defined in claim 4, whereinsaid other of said flange members is a stationary member unitary withsaid shaft member, and wherein said hub member is unitary with said onemovable flange member.
 13. In a sheave as defined in claim 12, whereinsaid stationary flange member and said shaft member, at the one hand,and said one movable flange member and said hub member, at the otherhand, are bonded to each other.
 14. In a sheave as defined in claim 3,and further comprising a shoulder portion in said hub member, saidshoulder portion constantly engaging said one of said ends of saidspring member.
 15. In a sheave as defined in claim 3, wherein saidretaining means comprises a bracket member fixedly secured at one end ofsaid shaft member and facing said one movable flange member.
 16. In asheave as defined in claim 3, wherein said retaining means comprises aflange member fixedly secured at one end of said shaft member and facingsaid one movable flange member.
 17. In a sheave as defined in claim 14,and further comprising a flange member seated against said shoulderportion intermediate the same and said one of said ends of said springmember.
 18. In a sheave as defined in claim
 1. Wherein said hub membercomprises at least one axially extending bore; and wherein said torquetransmitting means comprises at least one elongated rod member havingopposite ends with one of said opposite ends slidably received in saidat least one bore in said hub member, and a retaining ring fixedlymounted on said shaft member axially spaced from said hub member andfixed with the other of said opposite ends of said rod member.
 19. In asheave as defined in claim 18, said hub member comprising a firstportion facing said one movable flange member and a second portionfacing said retaining ring, said means for transmitting a biasing forceto said hub member comprising a roller bearing having an inner racesurrounding and fixed to said second portion of said hub member and anouter race rotatably surrounding said inner race, and wherein saidsecond portion of said hub member and said retaining ring haverespectively outer diameters not exceeding the inner diameter of saidinner race.
 20. In a sheave as defined in claim 19, wherein said atleast one bore in said hub member is provided with an inner sleevemember slidably guiding said at least one rod member.
 21. In a sheave asdefined in claim 20, wherein said inner sleeve member is made of aplastic material having a low coefficient of friction, said sleevehaving spaced ends and being provided with a slit extending from one tothe other of said spaced ends.
 22. In a sheave as defined in claim 1,wherein said other of said flange members is a reciprocable flangemember axially movable relative to said one of said movable flangemembers.